Mask apparatus

ABSTRACT

A face mask comprises a sealing collar ( 1 ) extending around the mouth with a shelf ( 4 ) extending under the nose supporting a gel insert ( 7 ) that makes sealing contact between the nostrils and a passage ( 6 ) through the shelf. A curved, rigid window ( 30 ) is a push fit in a central opening ( 2 ) of the collar ( 1 ) and has a gas inlet ( 33 ) attached with it so that the window can be removed or connected with the sealing collar as necessary. The collar ( 1 ) supported on the head by a harness ( 20 ) having two triangular portions ( 21 ) on opposite sides encircling respective ears.

TECHNICAL FIELD

This invention relates to mask apparatus of the kind including agenerally ring-shape sealing assembly adapted to be retained with thehead and to seal around at least the mouth of a user, and a gas inletfor supplying gas to the apparatus.

BACKGROUND ART

Masks are used to supply air or other gas to a patient via his mouth,nose or both. Masks take many different forms but the most commoncomprises a semi-rigid domed shell shaped to fit around the periphery ofboth the nose and mouth. The shell usually has some form of softermaterial around its edge, which provides a seal with the skin surface.An opening in the mask includes a coupling by which the mask isconnected to ventilation or anaesthesia equipment. The shell is usuallyretained in position by means of straps extending around the rear of thepatient's head and adjustably fastened to opposite sides of the shell.

There are various problems with existing masks. One problem is that ofachieving an effective seal with the contours of the face. Although itis not essential to provide a completely gas-tight seal with the skinsurface, if there is not a good fit, gas escaping between the mask andskin can cause discomfort to the patient. Attempts to increase the sealby tightening the straps can increase pressure on the face, which alsocauses discomfort. Another problem with masks that enclose the nose isthat some patients find them claustrophobic. Also, they often preventthe patient wearing spectacles. The straps used to hold the mask on thehead can often be difficult to position and adjust correctly. If themask has to be removed repeatedly to enable access to the patient'smouth it can be time-consuming to have to readjust and reposition thestraps of the mask each time it is removed and replaced.

One important use of breathing masks is in CPAP (continuous positiveairway pressure) or BIPAP (bidirectional positive airway pressure)ventilation for relieving sleep apnoea by keeping the airways free andopen when the muscles of the respiratory tract relax during sleep. Insleep apnoea applications the mask is often worn at home. It isparticularly important for such masks to be easy to use and comfortable.Where masks are used in hospitals this is often in intensive care unitsfor patients with heart failure, pulmonary disease or other respiratoryproblems. CPAP is used to inflate the lungs to a higher functionalcapacity to allow easier and more effective oxygen transfer.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide an alternative maskapparatus.

According to the present invention there is provided mask apparatus ofthe above-specified kind, characterised in that the sealing assembly hasa central opening located in the region of the mouth, and a removableclosure for securing with the central opening, and that the gas inlet ismounted with the closure.

The closure preferably includes a plate, which may be curved and rigid.The closure is preferably a push fit in the central opening. The sealingassembly may include a shelf adapted to extend beneath the nose of theuser and the shelf may support a compliant substance adapted to sealaround the nostrils. The shelf may have a passage therethrough adaptedto supply gas to the user's nose. The apparatus may include a harnesssecured with the sealing assembly and adapted to extend around the headof the user. The harness preferably includes two triangular portionsencircling respective ears of the user, both portions having a rear limbextending substantially vertically at the rear of the user's head andthe rear limbs being securable with one another at the rear of theuser's head. The sealing assembly may include an adhesive extendingaround its edge to contact the user's skin.

Mask apparatus according to the present invention will now be described,by way of example, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of the mask;

FIG. 2 is a partly cut-away side elevation view of the mask;

FIG. 3 is a perspective view illustrating removal of the closure means;and

FIG. 4 is a perspective view from the rear and above of the sealingassembly.

BEST MODES FOR CARRYING OUT THE INVENTION

The mask has a sealing assembly or collar 1 of a semi-rigid, imperviousfoamed plastics material. The collar 1 is of ring shape with a centralrectangular opening 2 located in front of the user's mouth. At its upperend, the assembly 1 has a shallow part-circular wall 3 extending arounda horizontal shelf 4, which forms the floor of a recess 5 in the upperend of the mask. The shelf 4 has a laterally-extending slot 6 through itpositioned to align with the nostrils of the user. The recess 5 containsa wedge-shape insert 7 of a gel or similar compliant material, whichalso has a lateral slot 8 that aligns with the slot 6 in the shelf 4 soas to provide a gas passage to the nostrils. The gel insert 7 sealsaround the nostrils of the user to confine gas flow through the slots 6and 8 to the nasal passages. The peripheral edge 9 of the collar 1extends under the chin, up opposite sides of the mouth and across thetop of the mouth between the mouth and the nose. The nature of thematerial of the collar 1 is such that its edge 9 conforms to thecontours of the face to form an effective seal.

The seal of the collar with the patient's skin can be improved by meansof an adhesive or gel strip extending around the edge 9 of the collar 1to contact the patient's skin.

The collar 1 is attached with a harness 20 by which the mask is securedto the user's head. The harness 20 is in two portions or halves 21 thatextend around the left and right sides of the user's head and that aresecured together at the back of the head by engaging cooperating hookand loop fabric fasteners 22. Each half 21 of the harness 20 is formedof a single piece of flexible, breathable, elastic material of generallytriangular shape with three limbs 23, 24 and 25 and a open centre 26.The forward end 27 of each half 21 of the harness is attached withopposite sides of the collar 1, two of the limbs 23 and 24 extendingrearwardly from the end 27 below and above the user's ear respectively.The ears are, therefore, accommodated in the open centre 26 andencircled by the respective harness portions 21. The third limb 25extends substantially vertically along the back of the head, joining therear ends of the limbs 23 and 24. The third limb 25 on each half 21 ofthe harness supports the hook and loop fasteners 22 so that these limbsare securable with one another at the rear of the head.

Where an adhesive is used to improve the seal around the edge 9 of thecollar 1, this may be sufficient to support the mask without the needfor a harness.

The mask assembly is completed by a closure in the form of a cover plateor window 30 fitted in the central opening 2 of the collar 1. The window30 is of a rigid but bendable transparent plastics material. It isgenerally rectangular in shape being curved substantially in asemi-circle across its width and being flat or slightly convex in avertical direction when viewed externally of the mask. The edge 31 ofthe window 30 is shaped so that it is a push or click fit in the opening2 of the collar 1, which is of a softer material. A catch tongue 32projects forwardly and upwardly from the centre of the upper edge of thewindow 30. Towards one side of the window 30 there is a gas inlet port33 connected with gas tubing 34, which extends along the side of thehead and is supported by a tab fastener 35 on the harness 30.

In use, the sealing collar 1 is first positioned over the mouth with thenose received in the recess 5. The two halves 21 of the harness 20 arethen passed around the side of the head and secured together at theback. In this state, the user is able to breathe through both his mouthand nose via the central opening 2 in the collar 1. When the patientneeds ventilation, the window 30 with the tubing 34 attached is clippedinto the opening 2. The tubing 34 is then secured with the harness 20 bymeans of the tab fastener 35. The transparent nature of the window 30enables the mouth area of the patient to be viewed readily.

Access to the mouth area can be obtained by removing the window 30,simply by gripping and pulling on the catch 32. This avoids the need toremove the mask in its entirety, which is a particular advantage where agel, adhesive or similar material is used to provide the seal or a partof the seal. The window 30 can be readily removed and replaced by theuser himself where ventilation is only required intermittently.

It will be appreciated that the mask could be arranged to enclose thenose as well as the mouth.

1. Mask apparatus including a generally ring-shape sealing assembly adapted to be retained with the head and to seal around at least the mouth of a user, a gas inlet for supplying gas to the apparatus, and a harness for retaining the sealing assembly with the head, characterized in that the sealing assembly has a central opening located in the region of the mouth and extending across the width of the mouth, and a closure in the form of a transparent window secured in the opening to extend across the width of the mouth, that the gas inlet is mounted with the window, and that the window is removable to leave the sealing assembly retained on the head by the harness such as to provide access to the region of the mouth via the opening.
 2. Mask apparatus according to claim 1, characterized in that the window is curved and rigid.
 3. Mask apparatus according to claim 1, characterized in that the window is a push fit in the central opening.
 4. Mask apparatus according to claim 1, characterized in that the sealing assembly includes a shelf adapted to extend beneath the nose of the user.
 5. Mask apparatus according to claim 4, characterized in that the shelf supports a compliant substance adapted to seal around the nostrils.
 6. Mask apparatus according to claim 5, characterized in that the shelf has a passage therethrough adapted to supply gas to the user's nose.
 7. Mask apparatus according to claim 4, characterized in that the shelf has a passage therethrough adapted to supply gas to the user's nose.
 8. Mask apparatus according to claim 1, characterized in that the harness comprises two triangular portions encircling respective ears of the user, that both portions have a rear limb extending substantially vertically at the rear of the user's head, and that the rear limbs are securable with one another at the rear of the user's head.
 9. Mask apparatus according to claim 1, characterized in that the sealing assembly includes an adhesive extending around its edge adapted to contact the user's skin.
 10. Mask apparatus according to claim 1, characterized in that the gas inlet is located to one side of the window.
 11. Mask apparatus including a generally ring-shape sealing assembly adapted to be retained with the head and to seal around at least the mouth of a user, and a gas inlet for supplying gas to the apparatus, characterized in that the sealing assembly includes a central opening located in the region of the mouth, a removable closure for securing with the central opening, the gas inlet being mounted with the closure, a shelf adapted to extend beneath the nose of the user, and a passage through the shelf adapted to supply gas to the user's nose.
 12. Mask apparatus according to claim 11, characterized in that the shelf supports a compliant substance adapted to seal around the nostrils of the user.
 13. Mask apparatus including a generally ring-shape sealing assembly adapted to be retained with the head and to seal around at least the mouth of a user, and a gas inlet for supplying gas to the apparatus, characterized in that the sealing assembly has a central opening located in the region of the mouth and extending across the width of the mouth, a removable closure in the form of a transparent window secured in the opening to extend across the width of the mouth, and a shelf adapted to extend beneath the nose of the user, and that the gas inlet is mounted with the window.
 14. Mask apparatus according to claim 13, characterized in that the shelf supports a compliant substance adapted to seal around the nostrils.
 15. Mask apparatus according to claim 13, characterized in that the shelf has a passage therethrough adapted to supply gas to the user's nose. 